Polenta, another name for cooked cornmeal or corn porridge, is naturally gluten-free. The only grains that do naturally contain gluten are wheat, rye and barley. Since so many other grains are processed in facilities that also handle wheat, rye and barley, however, some varieties of polenta may become contaminated with trace amounts of gluten.
Check the Label
Some brands of polenta print “gluten-free” directly onto their product labels for easy identification. Others don’t. Although it’s usually safe to assume that 100 percent polenta is made only from cornmeal, water and salt and has no gluten, check the label carefully to scan for allergy information or a statement such as, “Produced in a facility that also handles wheat, rye or barley.” Such a statement doesn’t mean cross-contamination has occurred, but it does increase the likelihood. Finally, if you’re eating a prepared polenta dish rather than something packaged, always ask whether there are any ingredients in your dish that may contain gluten.